The Federal Highway Administration (FHWA) developed a comprehensive program in 1986 to address the global need to identify, quantify, and rate culverts. The end product was the FHWA Culvert Inspection Manual. There is a critical need to develop an updated publication to incorporate new pipe products including materials (e.g., plastic pipe), coatings, and rehabilitative linings. These new products require the inclusion of new inspection guidelines and procedures for both culverts and storm drain systems. Facilities designed to accommodate aquatic organism passage (AOP), specifically open-bottom shapes and embedded closed-bottom culverts, are becoming a national focus and need more detailed assessment guidance than that found in the FHWA Culvert Inspection Manual. In addition, The FHWA Culvert Inspection Manual does not cover all of the elements of storm drain systems including: headwalls, wingwalls, junctions, manholes, and energy dissipaters. And, since the development of the FHWA manual, significant advancements have taken place on remote access inspection techniques such as digital camera technologies for assessing restricted-access pipes and culverts. Therefore, there is a need for a new inspection manual that incorporates new technologies, different material types, and systems components.
The objective of this research is to develop an inspection manual for assessing the condition of in-service culvert and storm drain systems to ensure system safety and performance and the economical use of owner resources. The manual will be presented in a format suitable for adoption by AASHTO and, as a minimum, will include the following: (1) catalog for distressed conditions, (2) inspection techniques, (3) condition assessment and rating criteria, (4) inspection reporting, and (5) best practices to help agencies manage their culvert inventory.
PHASE I—Develop Detailed Outline for Inspection Manual
Assemble information and propose an outline for the new inspection manual for culvert and storm drain systems of different materials. Information shall be assembled from FHWA Culvert Inspection Manual, technical literature, owners and industry experiences, ongoing NCHRP projects, and research findings from both foreign and domestic sources.
PHASE II—Catalog Distressed Conditions
Based on the approved work plan, develop a catalog of distressed conditions for culvert and storm drain systems including rehabilitated systems. Prepare a draft section for the manual. This draft section should be publication ready with appropriate level of details and illustrations.
PHASE III—Evaluate Inspection Techniques
Identify data collection requirements and develop metrics to select the appropriate inspection technologies for each distressed condition assessment considering different levels of inspection (e.g., routine or in-depth). Prepare a draft section of the inspection manual. This draft section should be publication ready with appropriate level of details and illustrations.
PHASE IV—Develop Condition Assessment and Rating Criteria
Develop criteria for condition assessment and rating considering all potential distressed conditions. Prepare a draft section of the manual. This draft section should be publication ready with appropriate level of details and illustrations.
PHASE V—Prepare Manual and Final Deliverables
Prepare inspection manual based on Phases I through IV. The manual shall include best practices for assessing the condition of in-service culvert and storm drain systems, suggested inspection reporting procedures to include an appraisal sheet format, and best existing practices to help agencies manage their culvert inventory (no database architecture and software development are intended). The guidelines will be presented in a format suitable for consideration by the AASHTO Highway Subcommittees on Bridges and Structures and Maintenance.
Prepare a preliminary draft final report that documents the entire research effort with an implementation strategy that considers technical and non-technical audiences. After consideration of panel comments, submit the revised final report. The inspection manual should be included as a stand-alone appendix.
STATUS: Research in progress.